Method for weaving fabric on a needle-type loom



0, 1966 K. c. BRUGGER 3,269,425

METHOD FOR WEAVING FABRIC ON A NEEDLE-TYPE LOOM Filed July 13, 1964 I NVENTOR. ZefZfZeZk 6 5/ United States Patent The present invention relates to a method for weaving, and more particularly a method for weaving upon a needle-type loom.

It is an object of the invention to provide a method for weaving whereby the weft or filler yarn of material so woven is resistant to being removed from the warp yarns, thereby providing a stronger and more lasting material.

It is a further object of the invention to provide a method for Weaving whereby the bulk and appearance of the material may be changed by the method of weaving the weft threads.

It is another object of the invention to provide an improved method for weaving elastic tape material.

It is a specific object of the invention to accomplish the above and other objects by a method of weaving upon a needle-type loom which forms the weft threads into twisted pairs.

Further objects and features of the invention pertain to the particular arrangement and steps of the method whereby the above-identified objects and other objects of the invention are attained.

The method of the invention will be better understood by reference to the following specification and the drawings forming a part thereof wherein:

FIGURE 1 is an idealized top plan view of a narrow web being woven utilizing the method of the invention, showing several completed weft pairs or loops, with the weaving needle being a new stroke;

FIGURE 2 is the representation of FIGURE 1 wherein the weaving needle has passed through the web and is beginning its withdrawal stroke; and

FIGURE 3 is the representation of FIGURE 1 wherein the weaving needle has completed its withdrawal, and the weft pair is being twisted.

Turning now to the drawings, there is shown therein an embodiment utilizing a method for weaving an improve-d fabric upon a needle-type loom in accordance with the invention. Generally described, the embodiment herein has a web 11 of parallel warp threads 10 through which is moved at right angles a weaving needle 1-2 carrying a weft or filler thread 14 through the web 11. The weft thread 14 is preferably caught over a holding looper or knitting needle 16 at the far side of the web 11, so that when the weaving needle 12 withdraws to its original position a pair or loop 15 of weft threads is left in the warp threads. During or after the withdrawal of the weaving needle 12 from the warp threads, the holding looper 16 is given a plurality of turns or twists, so that the weft loop 15 is twisted, thereby forming a fabric material in which the weft or filler threads are highly resistant to pulling out, and the fabric may be provided with increased bulk and improved appearance.

Beginning with FIGURE 1, the weaving needle 12 is shown in its initial position preparatory to beginning a new pass or pick through the warp threads. The weaving needle 12 here has an eye 17 through which the weft threads 10 are fed from a conventional yarn supply (not shown), generally under tension. Prior to the passage of the weaving needle through the warp threads, alternate warp threads are raised or lowered in the conventional manner so that two separate planes of warp threads are formed, thus forming what is known as the warp shed, between which the weaving needle 12 passes. For the purposes of the description herein and the accompanying claims, any loom in which weft threads are placed in loops or pairs within the same warp shed, as is intended for the method of the invention, is included within the term needle-type loom.

FIGURE 2 shows a next step wherein the weaving needle 12 has been passed through the warp shed from one side of the web 11 to the other. At this point (prior to the withdrawal stroke of the weaving needle), the weft thread 14 must be caught or held in some manner until the Weaving needle 12 is fully with-drawn from the web. This is normally accomplished by catching or holding a loop end 19 of the weft thread at the far side of the web. As shown in FIGURE 2, this is accomplished in the embodiment described herein by means of a holding looper 16. The holding looper 16 illustrated here is selected merely by Way of example, as numerous devices for catching a loop end of the weft thread are available. At the end of the holding looper 16 there is provided a hook 18 adapted to catch the weft thread. This catch occurs when the weaving needle 12 has passed through the web 11 and is extended slightly beyond the edge of the web, so that the weft yarn 14 being carried through the eye 17 passes over the end of the hook 18 and is caught. Consequently, when the weaving needle 12 begins its withdrawal back through the warp shed the hook 18 prevents the weft thread already laid from being withdrawn, and also causes additional weft thread to feed through the eye -17, thus forming the continuous adjacent pair or loop 15 of weft thread within the warp shed, having a loop apex at the loop end 19 and a mouth or open end at the opposite end.

At this point in the weaving process, as shown in FIG- URE 3, the method of the invention departs completely from the prior art. Rather than allow the completed loop of weft threads to remain in a smooth parallel path, thus being easily removable from the warp threads, the two threads forming the loop of weft threads are twisted about each other to form a continuous twisted pair. In the embodiment shown here this is accomplished simply and rapidly by twisting the holding looper 16 which, as described above, is holding the loop end 19 in its hook 18. For the holding looper 16 shown this way be accomplished simply by spinning the holding looper about its own axis by any convenient means (not shown). The number of spins given the holder looper 16 will, of course, determine the number of twists imparted to the pair 15 of weft threads. And the number of twists desired for the given weaving operation will depend upon the width of the web being woven, upon the bulk and texture desired for the material and other factors. Varying the amount of twist given to the pair of weft threads will affect the texture and density of the material and the resistance of the weft threads to removal from the warp threads. The threads of each pair are spun about each other, rather than about their individual axes. It would be possible (but not necessarily desirable) for the yarns to also be twisted about their individual axes prior to or during the weaving process.

It is important to note that the twists given the pair of weft threads may be accomplished at any time after the loop end 19 is caught during the weaving cycle. In other words, the loop end may be spun during the withdrawal of the weaving needle 12 from the web, and the entire twisting operation may be completed by the time the weaving needle 12 has withdrawn from the web. However, it is also possible, as shown in FIGURE 3, to twist the weft pair 15 after the weaving needle .12 has been withdrawn.

After each twisted pair of weft threads is formed within a warp shed in the manner described above, a conventional weaving process may be continued. That is, the holding looper is withdrawn from the end loop (for example, by depressing the holding looper slightly so that the hook 18 withdraws from the end loop) and the warp shed is reversed, prior to the next weaving needle insertion, by reversing the positions of the alternate warp threads, in the conventional weaving manner. Also the warp threads are all advanced and the weft threads compressed. The weaving method of the invention is repeated for each pick, thereby Weaving a complete fabric having improved qualities. The finished fabric has, of course, a much more closely spaced structure than that shown for convenience in the drawings.

Conventional practice in weaving fabrics on needletype looms generally employs a further step not discussed above, that of knitting or tying in some manner the end loops of the weft pairs, as by continuously inserting an additional warp thread through the loop ends, or knitting the loop ends together, as, for example, is illustrated in Patent No. 2,584,891 to C. F. Libby. This step may, of course, also be utilized in connection with the method of the invention. In fact, the holding looper 16 may be used to perform the multiple functions of knitting, holding the weft loop end, and/or spinning the loop. However, with the improved strength and resistance to pulling of the weft threads of fabric woven by the method of the invention, this practice of anchoring the end loops is not as important as it is for the weaving methods of the prior art.

The results accompanying the employment of the method of the invention include the weaving of a fabric with increased wear and strength, increased bulk and an improved texture; yet at the same time the weft yarn may be supplied to the weaving needle or needles as a single untwisted yarn, which is much more easily handled and woven than a twisted pair of yarns.

The twisting operation on the weft threads causes these threads to cling and tangle with the warp threads so that they have a high resistance to pulling out even where they have been torn or broken into relatively short lengths. The conventional untwisted parallel pair configuration of weft threads on needle-type looms generally has less resistance to weft thread pulling than the weft thread configuration produced by conventional weaving. Thus an inherent disadvantage of needle-type looms is overcome. Overcoming this disadvantage allows needletype looms, which have a higher speed than conventional looms, to be utilized in many new applications.

The method of the invention is particularly suited for weaving elastic tapes or belts such as are utilized in underwear and other clothing articles. In these fabrics, where the warp threads generally are an elastic material, the weft or filter threads have a particular tendency to pull out from the warp threads. Thus the method of the invention provides an elastic tape having improved wear resistance, as the weft threads will not work out to expose the elastic threads to damage, which they are easily subject to if not protected by the filler threads.

Numerous variations and modifications of the invention will be obvious to one with ordinary skill in the art, and the method of the invention is not in any Way limited to its practice with any of the structures or devices described above. It is intended to cover in the appended claim all variations and modifications of the invention as fall within the true spirit and scope of the invention.

What is claimed is: A process for weaving improved elastic tape fabric on a needletype loom, including the steps of:

forming an open warp shed of elastic warp threads, forming a looped pair of filler threads within said open warp .shed, said looped pair of filler threads having substantially the same width as said warp shed,

twisting said looped pair of filler threads continuously about one another within said open warp shed, said twisting being continued until said looped pair of filler threads have substantially increased in bulk,

reversing said open warp shed only after said twisting is completed,

and repeating said steps to form said fabric.

References Cited by the Examiner UNITED STATES PATENTS 9/1910 Huebler 139118 7/1924- Walliser et a1. 139-418 5/1926 Nelson 139118 9/1935 Best 139124 5/1942 Moore 139124 

